1. Field of the Invention
The present invention relates to industrial vehicles, such as lift trucks; and more particularly to a system for sensing performance characteristics of an industrial vehicle and using those characteristics to manage the operation of the vehicle.
2. Description of the Related Art
Industrial vehicles of various types, including material handling vehicles, are used to move items inside a factory, a warehouse, a freight transfer station, a store, or other type of facility. In order to effectively and efficiently operate a warehouse, for example, it is important to ensure that the equipment and employees are as productive as possible. Recent studies, in fact, have indicated that 70 percent to 80 percent of the cost of owning and operating an industrial vehicle is attributed to labor. For a warehouse to compete on the global level, continually improving operator productivity is vital to reducing costs. To meet these goals, warehouse management systems are frequently employed to control inventory, ensure proper maintenance of equipment, and to monitor operator and equipment efficiency. In these warehouse management systems, a centralized computer system monitors inventory flow, use of the industrial vehicle, vehicle maintenance status, and operator performance.
To provide these functions, data is gathered from each industrial vehicle. In order to gather the data, wiring harnesses and sensors typically are added to the industrial vehicle after manufacture, often after delivery to the warehouse. These wiring harnesses connect sensors and other devices to a dedicated onboard computer, and provide a number of connection points within the vehicle. Because of the large number of connection points, these add-on systems are susceptible to failure. In addition, the post-manufacture sensors provide only limited information and can be inaccurate. Thus a more optimized system for monitoring a vehicle's performance and operation is desired.
Safe operation of an industrial vehicle requires, operator training and skill, good lift truck maintenance and a safe workplace with appropriately configured lift trucks. Fragile loads sometimes fall off and are damaged when the operator drives the industrial vehicle too fast for conditions in the warehouse. Also certain warehouse environments, such as cold storage areas and areas with potentially explosive atmospheres, require special industrial vehicles that are designed to operate in such environments. For example, Standard UL 583, promulgated by the Underwriters Laboratories of Northbrook, Ill., U.S.A., specifies “spark proof” characteristics for a Type EE industrial vehicle for use in areas where flammable materials are stored. A potential hazard exists when a vehicle that is not Type EE rated is used in such storage areas.
As industrial vehicles have gotten more sophisticated, with computerized controls for example, maintenance practices have had to change accordingly. A particular lift truck model may have numerous optional features that a user may choose to have added during manufacture. Typically a dealer dispatches a service technician to the warehouse or factory to perform maintenance and repairs on an industrial vehicle. The service technician needs to know exactly which application specific options and features have been incorporated into the vehicle being serviced and may need access to any of several service manuals associated with the particular vehicle model and the installed options and features. This means that in order to service a complete product line of industrial vehicles and different models which have been manufactured over many years, the service technician has to be able to access a sizable library of manuals and supplementary materials when in a warehouse or factory.